Curveball

Lore & Background

The curveball is a popular and effective pitch in professional baseball, but it is not particularly widespread in leagues with players younger than college level. This is with regard for the safety of the pitcher, not because of its difficulty, though the pitch is widely considered difficult to learn as it requires some degree of mastery and the ability to pinpoint the thrown ball's location.

Reader's Guide

The curveball is typically gripped in a manner similar to holding a cup or a glass. The pitcher positions the middle finger along and parallel to one of the ball's long seams, while the thumb is placed on the seam opposite, forming a 'C shape' when viewed from above. The delivery involves snapping the arm and wrist in a downward motion at the top of the throwing arc. The ball first leaves contact with the thumb and tumbles over the index finger, imparting forward spin. The amount of break depends on how hard the pitcher can snap the throw off. Curveballs are thrown with considerably less speed than fastballs, averaging between 65 and 80 mph at the major collegiate level and above.

Did You Know?

• Varieties of curveball include the 12–6 curveball, power curveball, and the knuckle curve.
• A typical MLB curveball as of the 2025 MLB Season is approximately 80.5 mph.
• When thrown correctly, a curveball could have a break from seven to as much as 20 inches in comparison to the same pitcher's fastball.
• The curveball is considered a more advanced pitch and poses inherent risk of injury to a pitcher's elbow and shoulder.